ora-38763: flashback not started; enabled threads have changed

Cause: A FLASHBACK DATABASE command did not start. The set of enabled threads changed during the time to flash back.
Action: The flashback cannot be performed. Perform a restore and an incomplete recovery instead.

no se ha iniciado flashback; han cambiado los threads activados
Le flashback n'a pas été lancé ; les threads actifs ont été modifiés.
Flashback nicht gestartet; aktivierte Threads wurden geändert
o flashback não foi iniciado; os processos leves activados foram alterados
ora-26041 ora-31063 ora-48496